Commit c0d498a1 authored by Nicolin Chen's avatar Nicolin Chen Committed by Jason Gunthorpe
Browse files

iommufd: Introduce iommufd_object_alloc_ucmd helper 

An object allocator needs to call either iommufd_object_finalize() upon a
success or iommufd_object_abort_and_destroy() upon an error code.

To reduce duplication, store a new_obj in the struct iommufd_ucmd and call
iommufd_object_finalize/iommufd_object_abort_and_destroy() accordingly in
the main function.

Similar to iommufd_object_alloc() and __iommufd_object_alloc(), add a pair
of helpers: __iommufd_object_alloc_ucmd() and iommufd_object_alloc_ucmd().

Link: https://patch.msgid.link/r/e7206d4227844887cc8dbf0cc7b0242580fafd9d.1749882255.git.nicolinc@nvidia.com


Suggested-by: default avatarJason Gunthorpe <jgg@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>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Acked-by: default avatarPranjal Shrivastava <praan@google.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 17a93473

drivers/iommu/iommufd/iommufd_private.h

+26 −0
Original line number Diff line number Diff line
@@ -135,6 +135,7 @@ struct iommufd_ucmd { 
	void __user *ubuffer;

	u32 user_size;

	void *cmd;

	struct iommufd_object *new_obj;

};



int iommufd_vfio_ioctl(struct iommufd_ctx *ictx, unsigned int cmd,
@@ -230,6 +231,11 @@ iommufd_object_put_and_try_destroy(struct iommufd_ctx *ictx, 
	iommufd_object_remove(ictx, obj, obj->id, 0);

}



/*

 * Callers of these normal object allocators must call iommufd_object_finalize()

 * to finalize the object, or call iommufd_object_abort_and_destroy() to revert

 * the allocation.

 */

struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,

					     size_t size,

					     enum iommufd_object_type type);
@@ -246,6 +252,26 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, 
#define iommufd_object_alloc(ictx, ptr, type) \

	__iommufd_object_alloc(ictx, ptr, type, obj)



/*

 * Callers of these _ucmd allocators should not call iommufd_object_finalize()

 * or iommufd_object_abort_and_destroy(), as the core automatically does that.

 */

struct iommufd_object *

_iommufd_object_alloc_ucmd(struct iommufd_ucmd *ucmd, size_t size,

			   enum iommufd_object_type type);



#define __iommufd_object_alloc_ucmd(ucmd, ptr, type, obj)                      \

	container_of(_iommufd_object_alloc_ucmd(                               \

			     ucmd,                                             \

			     sizeof(*(ptr)) + BUILD_BUG_ON_ZERO(               \

						      offsetof(typeof(*(ptr)), \

							       obj) != 0),     \

			     type),                                            \

		     typeof(*(ptr)), obj)



#define iommufd_object_alloc_ucmd(ucmd, ptr, type) \

	__iommufd_object_alloc_ucmd(ucmd, ptr, type, obj)



/*

 * The IO Address Space (IOAS) pagetable is a virtual page table backed by the

 * io_pagetable object. It is a user controlled mapping of IOVA -> PFNs. The

drivers/iommu/iommufd/main.c

+25 −0
Original line number Diff line number Diff line
@@ -61,6 +61,24 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, 
	return ERR_PTR(rc);

}



struct iommufd_object *_iommufd_object_alloc_ucmd(struct iommufd_ucmd *ucmd,

						  size_t size,

						  enum iommufd_object_type type)

{

	struct iommufd_object *new_obj;



	/* Something is coded wrong if this is hit */

	if (WARN_ON(ucmd->new_obj))

		return ERR_PTR(-EBUSY);



	new_obj = _iommufd_object_alloc(ucmd->ictx, size, type);

	if (IS_ERR(new_obj))

		return new_obj;



	ucmd->new_obj = new_obj;

	return new_obj;

}



/*

 * Allow concurrent access to the object.

 *
@@ -448,6 +466,13 @@ static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd, 
	if (ret)

		return ret;

	ret = op->execute(&ucmd);



	if (ucmd.new_obj) {

		if (ret)

			iommufd_object_abort_and_destroy(ictx, ucmd.new_obj);

		else

			iommufd_object_finalize(ictx, ucmd.new_obj);

	}

	return ret;

}