Commit 1c9dc074 authored by Yi Liu's avatar Yi Liu Committed by Alex Williamson
Browse files

iommufd: Add iommufd_ctx_from_fd() 



It's common to get a reference to the iommufd context from a given file
descriptor. So adds an API for it. Existing users of this API are compiled
only when IOMMUFD is enabled, so no need to have a stub for the IOMMUFD
disabled case.

Tested-by: default avatarYanting Jiang <yanting.jiang@intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarYi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-21-yi.l.liu@intel.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 5c6de3ea

drivers/iommu/iommufd/main.c

+24 −0
Original line number Diff line number Diff line
@@ -377,6 +377,30 @@ struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) 
}

EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_file, IOMMUFD);



/**

 * iommufd_ctx_from_fd - Acquires a reference to the iommufd context

 * @fd: File descriptor to obtain the reference from

 *

 * Returns a pointer to the iommufd_ctx, otherwise ERR_PTR. On success

 * the caller is responsible to call iommufd_ctx_put().

 */

struct iommufd_ctx *iommufd_ctx_from_fd(int fd)

{

	struct file *file;



	file = fget(fd);

	if (!file)

		return ERR_PTR(-EBADF);



	if (file->f_op != &iommufd_fops) {

		fput(file);

		return ERR_PTR(-EBADFD);

	}

	/* fget is the same as iommufd_ctx_get() */

	return file->private_data;

}

EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_fd, IOMMUFD);



/**

 * iommufd_ctx_put - Put back a reference

 * @ictx: Context to put back

include/linux/iommufd.h

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ void iommufd_ctx_get(struct iommufd_ctx *ictx); 


#if IS_ENABLED(CONFIG_IOMMUFD)

struct iommufd_ctx *iommufd_ctx_from_file(struct file *file);

struct iommufd_ctx *iommufd_ctx_from_fd(int fd);

void iommufd_ctx_put(struct iommufd_ctx *ictx);

bool iommufd_ctx_has_group(struct iommufd_ctx *ictx, struct iommu_group *group);