Commit 4601cd2d authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu: Add ops->domain_alloc_paging() 



This callback requests the driver to create only a __IOMMU_DOMAIN_PAGING
domain, so it saves a few lines in a lot of drivers needlessly checking
the type.

More critically, this allows us to sweep out all the
IOMMU_DOMAIN_UNMANAGED and IOMMU_DOMAIN_DMA checks from a lot of the
drivers, simplifying what is going on in the code and ultimately removing
the now-unused special cases in drivers where they did not support
IOMMU_DOMAIN_DMA.

domain_alloc_paging() should return a struct iommu_domain that is
functionally compatible with ARM_DMA_USE_IOMMU, dma-iommu.c and iommufd.

Be forwards looking and pass in a 'struct device *' argument. We can
provide this when allocating the default_domain. No drivers will look at
this.

Tested-by: default avatarSteven Price <steven.price@arm.com>
Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/22-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 8359cf39

drivers/iommu/iommu.c

+14 −3
Original line number Diff line number Diff line
@@ -2041,6 +2041,7 @@ void iommu_set_fault_handler(struct iommu_domain *domain, 
EXPORT_SYMBOL_GPL(iommu_set_fault_handler);



static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops,

						 struct device *dev,

						 unsigned int type)

{

	struct iommu_domain *domain;
@@ -2048,8 +2049,13 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, 


	if (alloc_type == IOMMU_DOMAIN_IDENTITY && ops->identity_domain)

		return ops->identity_domain;



	else if (type & __IOMMU_DOMAIN_PAGING && ops->domain_alloc_paging)

		domain = ops->domain_alloc_paging(dev);

	else if (ops->domain_alloc)

		domain = ops->domain_alloc(alloc_type);

	else

		return NULL;



	if (!domain)

		return NULL;
@@ -2074,14 +2080,19 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, 
static struct iommu_domain *

__iommu_group_domain_alloc(struct iommu_group *group, unsigned int type)

{

	return __iommu_domain_alloc(group_iommu_ops(group), type);

	struct device *dev =

		list_first_entry(&group->devices, struct group_device, list)

			->dev;



	return __iommu_domain_alloc(group_iommu_ops(group), dev, type);

}



struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)

{

	if (bus == NULL || bus->iommu_ops == NULL)

		return NULL;

	return __iommu_domain_alloc(bus->iommu_ops, IOMMU_DOMAIN_UNMANAGED);

	return __iommu_domain_alloc(bus->iommu_ops, NULL,

				    IOMMU_DOMAIN_UNMANAGED);

}

EXPORT_SYMBOL_GPL(iommu_domain_alloc);

include/linux/iommu.h

+3 −0
Original line number Diff line number Diff line
@@ -239,6 +239,8 @@ struct iommu_iotlb_gather { 
 *           use. The information type is one of enum iommu_hw_info_type defined

 *           in include/uapi/linux/iommufd.h.

 * @domain_alloc: allocate iommu domain

 * @domain_alloc_paging: Allocate an iommu_domain that can be used for

 *                       UNMANAGED, DMA, and DMA_FQ domain types.

 * @probe_device: Add device to iommu driver handling

 * @release_device: Remove device from iommu driver handling

 * @probe_finalize: Do final setup work after the device is added to an IOMMU
@@ -273,6 +275,7 @@ struct iommu_ops { 


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

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

	struct iommu_domain *(*domain_alloc_paging)(struct device *dev);



	struct iommu_device *(*probe_device)(struct device *dev);

	void (*release_device)(struct device *dev);