Commit e8f52d84 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu: Add generic_single_device_group() 



This implements the common pattern seen in drivers of a single iommu_group
for the entire iommu driver instance. Implement this in core code so the
drivers that want this can select it from their ops.

Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v1-c869a95191f2+5e8-iommu_single_grp_jgg@nvidia.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent e946f8e3

drivers/iommu/iommu.c

+27 −1
Original line number Diff line number Diff line
@@ -292,6 +292,10 @@ void iommu_device_unregister(struct iommu_device *iommu) 
	spin_lock(&iommu_device_lock);

	list_del(&iommu->list);

	spin_unlock(&iommu_device_lock);



	/* Pairs with the alloc in generic_single_device_group() */

	iommu_group_put(iommu->singleton_group);

	iommu->singleton_group = NULL;

}

EXPORT_SYMBOL_GPL(iommu_device_unregister);
@@ -406,6 +410,7 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops) 
		ret = PTR_ERR(iommu_dev);

		goto err_module_put;

	}

	dev->iommu->iommu_dev = iommu_dev;



	ret = iommu_device_link(iommu_dev, dev);

	if (ret)
@@ -420,7 +425,6 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops) 
	}

	dev->iommu_group = group;



	dev->iommu->iommu_dev = iommu_dev;

	dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev);

	if (ops->is_attach_deferred)

		dev->iommu->attach_deferred = ops->is_attach_deferred(dev);
@@ -434,6 +438,7 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops) 
err_module_put:

	module_put(ops->owner);

err_free:

	dev->iommu->iommu_dev = NULL;

	dev_iommu_free(dev);

	return ret;

}
@@ -1637,6 +1642,27 @@ struct iommu_group *generic_device_group(struct device *dev) 
}

EXPORT_SYMBOL_GPL(generic_device_group);



/*

 * Generic device_group call-back function. It just allocates one

 * iommu-group per iommu driver instance shared by every device

 * probed by that iommu driver.

 */

struct iommu_group *generic_single_device_group(struct device *dev)

{

	struct iommu_device *iommu = dev->iommu->iommu_dev;



	if (!iommu->singleton_group) {

		struct iommu_group *group;



		group = iommu_group_alloc();

		if (IS_ERR(group))

			return group;

		iommu->singleton_group = group;

	}

	return iommu_group_ref_get(iommu->singleton_group);

}

EXPORT_SYMBOL_GPL(generic_single_device_group);



/*

 * Use standard PCI bus topology, isolation features, and DMA alias quirks

 * to find or create an IOMMU group for a device.

include/linux/iommu.h

+3 −0
Original line number Diff line number Diff line
@@ -378,6 +378,7 @@ struct iommu_domain_ops { 
 * @list: Used by the iommu-core to keep a list of registered iommus

 * @ops: iommu-ops for talking to this iommu

 * @dev: struct device for sysfs handling

 * @singleton_group: Used internally for drivers that have only one group

 * @max_pasids: number of supported PASIDs

 */

struct iommu_device {
@@ -385,6 +386,7 @@ struct iommu_device { 
	const struct iommu_ops *ops;

	struct fwnode_handle *fwnode;

	struct device *dev;

	struct iommu_group *singleton_group;

	u32 max_pasids;

};
@@ -648,6 +650,7 @@ extern struct iommu_group *pci_device_group(struct device *dev); 
extern struct iommu_group *generic_device_group(struct device *dev);

/* FSL-MC device grouping function */

struct iommu_group *fsl_mc_device_group(struct device *dev);

extern struct iommu_group *generic_single_device_group(struct device *dev);



/**

 * struct iommu_fwspec - per-device IOMMU instance data