Commit bf8aff29 authored by Vasant Hegde's avatar Vasant Hegde Committed by Joerg Roedel
Browse files

iommu: Introduce iommu_group_mutex_assert() 



Add function to check iommu group mutex lock. So that device drivers can
rely on group mutex lock instead of adding another driver level lock
before modifying driver specific device data structure.

Suggested-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240205115615.6053-10-vasant.hegde@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent b2e8a7f5

drivers/iommu/iommu.c

+19 −0
Original line number Diff line number Diff line
@@ -1248,6 +1248,25 @@ void iommu_group_remove_device(struct device *dev) 
}

EXPORT_SYMBOL_GPL(iommu_group_remove_device);



#if IS_ENABLED(CONFIG_LOCKDEP) && IS_ENABLED(CONFIG_IOMMU_API)

/**

 * iommu_group_mutex_assert - Check device group mutex lock

 * @dev: the device that has group param set

 *

 * This function is called by an iommu driver to check whether it holds

 * group mutex lock for the given device or not.

 *

 * Note that this function must be called after device group param is set.

 */

void iommu_group_mutex_assert(struct device *dev)

{

	struct iommu_group *group = dev->iommu_group;



	lockdep_assert_held(&group->mutex);

}

EXPORT_SYMBOL_GPL(iommu_group_mutex_assert);

#endif



static struct device *iommu_group_first_dev(struct iommu_group *group)

{

	lockdep_assert_held(&group->mutex);

include/linux/iommu.h

+8 −0
Original line number Diff line number Diff line
@@ -1356,6 +1356,14 @@ static inline ioasid_t iommu_alloc_global_pasid(struct device *dev) 
static inline void iommu_free_global_pasid(ioasid_t pasid) {}

#endif /* CONFIG_IOMMU_API */



#if IS_ENABLED(CONFIG_LOCKDEP) && IS_ENABLED(CONFIG_IOMMU_API)

void iommu_group_mutex_assert(struct device *dev);

#else

static inline void iommu_group_mutex_assert(struct device *dev)

{

}

#endif



/**

 * iommu_map_sgtable - Map the given buffer to the IOMMU domain

 * @domain:	The IOMMU domain to perform the mapping