Commit 4f2e59cc authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

iommu: Add iommu_copy_struct_from_full_user_array helper 

The iommu_copy_struct_from_user_array helper can be used to copy a single
entry from a user array which might not be efficient if the array is big.

Add a new iommu_copy_struct_from_full_user_array to copy the entire user
array at once. Update the existing iommu_copy_struct_from_user_array kdoc
accordingly.

Link: https://patch.msgid.link/r/5cd773d9c26920c5807d232b21d415ea79172e49.1730836308.git.nicolinc@nvidia.com


Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 54ce69e3

include/linux/iommu.h

+47 −1
Original line number Diff line number Diff line
@@ -493,7 +493,9 @@ static inline int __iommu_copy_struct_from_user_array( 
 * @index: Index to the location in the array to copy user data from

 * @min_last: The last member of the data structure @kdst points in the

 *            initial version.

 * Return 0 for success, otherwise -error.

 *

 * Copy a single entry from a user array. Return 0 for success, otherwise

 * -error.

 */

#define iommu_copy_struct_from_user_array(kdst, user_array, data_type, index, \

					  min_last)                           \
@@ -501,6 +503,50 @@ static inline int __iommu_copy_struct_from_user_array( 
		kdst, user_array, data_type, index, sizeof(*(kdst)),          \

		offsetofend(typeof(*(kdst)), min_last))



/**

 * iommu_copy_struct_from_full_user_array - Copy iommu driver specific user

 *         space data from an iommu_user_data_array

 * @kdst: Pointer to an iommu driver specific user data that is defined in

 *        include/uapi/linux/iommufd.h

 * @kdst_entry_size: sizeof(*kdst)

 * @user_array: Pointer to a struct iommu_user_data_array for a user space

 *              array

 * @data_type: The data type of the @kdst. Must match with @user_array->type

 *

 * Copy the entire user array. kdst must have room for kdst_entry_size *

 * user_array->entry_num bytes. Return 0 for success, otherwise -error.

 */

static inline int

iommu_copy_struct_from_full_user_array(void *kdst, size_t kdst_entry_size,

				       struct iommu_user_data_array *user_array,

				       unsigned int data_type)

{

	unsigned int i;

	int ret;



	if (user_array->type != data_type)

		return -EINVAL;

	if (!user_array->entry_num)

		return -EINVAL;

	if (likely(user_array->entry_len == kdst_entry_size)) {

		if (copy_from_user(kdst, user_array->uptr,

				   user_array->entry_num *

					   user_array->entry_len))

			return -EFAULT;

	}



	/* Copy item by item */

	for (i = 0; i != user_array->entry_num; i++) {

		ret = copy_struct_from_user(

			kdst + kdst_entry_size * i, kdst_entry_size,

			user_array->uptr + user_array->entry_len * i,

			user_array->entry_len);

		if (ret)

			return ret;

	}

	return 0;

}



/**

 * struct iommu_ops - iommu ops and capabilities

 * @capable: check capability