[PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper

[Zhangfei Gao]

On Sat, 26 Oct 2024 at 07:51, Nicolin Chen <nicolinc at nvidia.com> wrote:
>
> This avoids a bigger trouble of exposing struct iommufd_device and struct
> iommufd_vdevice in the public header.
>
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
> ---
>  include/linux/iommufd.h        |  8 ++++++++
>  drivers/iommu/iommufd/driver.c | 13 +++++++++++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
> index 0287a6d00192..dc174d02132b 100644
> --- a/include/linux/iommufd.h
> +++ b/include/linux/iommufd.h
> @@ -184,6 +184,8 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
>  struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
>                                              size_t size,
>                                              enum iommufd_object_type type);
> +struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
> +                                      unsigned long vdev_id);
>  #else /* !CONFIG_IOMMUFD_DRIVER */
>  static inline struct iommufd_object *
>  _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
> @@ -191,6 +193,12 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
>  {
>         return ERR_PTR(-EOPNOTSUPP);
>  }
> +
> +static inline struct device *
> +iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
> +{
> +       return NULL;
> +}
>  #endif /* CONFIG_IOMMUFD_DRIVER */
>
>  /*
> diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
> index c0876d3f91c7..3604443f82a1 100644
> --- a/drivers/iommu/iommufd/driver.c
> +++ b/drivers/iommu/iommufd/driver.c
> @@ -36,3 +36,16 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
>         return ERR_PTR(rc);
>  }
>  EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD);
> +
> +/* Caller should xa_lock(&viommu->vdevs) to protect the return value */
> +struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
> +                                      unsigned long vdev_id)
> +{
> +       struct iommufd_vdevice *vdev;
> +
> +       lockdep_is_held(&viommu->vdevs.xa_lock);
> +
> +       vdev = xa_load(&viommu->vdevs, vdev_id);
> +       return vdev ? vdev->idev->dev : NULL;
> +}

Got this error?

ld: Unexpected GOT/PLT entries detected!
ld: Unexpected run-time procedure linkages detected!
ld: drivers/iommu/iommufd/driver.o: in function `iommufd_viommu_find_dev':
linux/drivers/iommu/iommufd/driver.c:47: undefined reference to
`lockdep_is_held'
make[2]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
make[1]: *** [/home/linaro/iommufd/linux/Makefile:1166: vmlinux] Error 2
make: *** [Makefile:224: __sub-make] Error 2