On Fri, 2022-09-23 at 11:26 +0200, Christoph Hellwig wrote:
> Instead of abusing struct attribute_group to control initialization
> of
> struct mdev_type, just define the actual attributes in the
> mdev_driver,
> allocate the mdev_type structures in the caller and pass them to
> mdev_register_parent.
>
> This allows the caller to use container_of to get at the containing
> structure and thus significantly simplify the code.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Reviewed-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> Reviewed-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx>
> ---
> .../driver-api/vfio-mediated-device.rst | 2 +-
> drivers/gpu/drm/i915/gvt/gvt.h | 3 +-
> drivers/gpu/drm/i915/gvt/kvmgt.c | 102 +++-------------
> --
> drivers/gpu/drm/i915/gvt/vgpu.c | 13 ++-
> drivers/s390/cio/vfio_ccw_drv.c | 6 +-
> drivers/s390/cio/vfio_ccw_ops.c | 14 +--
> drivers/s390/cio/vfio_ccw_private.h | 2 +
> drivers/s390/crypto/vfio_ap_ops.c | 19 ++--
> drivers/s390/crypto/vfio_ap_private.h | 2 +
> drivers/vfio/mdev/mdev_core.c | 31 ++----
> drivers/vfio/mdev/mdev_driver.c | 5 +-
> drivers/vfio/mdev/mdev_private.h | 8 --
> drivers/vfio/mdev/mdev_sysfs.c | 91 ++++------------
> include/linux/mdev.h | 26 +++--
> samples/vfio-mdev/mbochs.c | 57 ++++------
> samples/vfio-mdev/mdpy.c | 50 ++++-----
> samples/vfio-mdev/mtty.c | 60 +++++------
> 17 files changed, 165 insertions(+), 326 deletions(-)
>
> diff --git a/Documentation/driver-api/vfio-mediated-device.rst
> b/Documentation/driver-api/vfio-mediated-device.rst
> index cd1667608ab5d..ff7342d2e332d 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -103,7 +103,7 @@ structure to represent a mediated device's
> driver::
> struct mdev_driver {
> int (*probe) (struct mdev_device *dev);
> void (*remove) (struct mdev_device *dev);
> - struct attribute_group **supported_type_groups;
> + const struct attribute * const *types_attrs;
> struct device_driver driver;
> };
>
> diff --git a/drivers/gpu/drm/i915/gvt/gvt.h
> b/drivers/gpu/drm/i915/gvt/gvt.h
> index fa4a56b50c828..db182066d56c9 100644
> --- a/drivers/gpu/drm/i915/gvt/gvt.h
> +++ b/drivers/gpu/drm/i915/gvt/gvt.h
> @@ -310,8 +310,8 @@ struct intel_vgpu_config {
> const char *name;
> };
>
> -#define NR_MAX_INTEL_VGPU_TYPES 20
> struct intel_vgpu_type {
> + struct mdev_type type;
> char name[16];
> const struct intel_vgpu_config *conf;
> unsigned int avail_instance;
> @@ -339,6 +339,7 @@ struct intel_gvt {
> struct notifier_block
> shadow_ctx_notifier_block[I915_NUM_ENGINES];
> DECLARE_HASHTABLE(cmd_table, GVT_CMD_HASH_BITS);
> struct mdev_parent parent;
> + struct mdev_type **mdev_types;
> struct intel_vgpu_type *types;
> unsigned int num_types;
> struct intel_vgpu *idle_vgpu;
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 29531b797010f..ce6b8cb37be0c 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -117,17 +117,10 @@ static ssize_t available_instances_show(struct
> mdev_type *mtype,
> struct mdev_type_attribute
> *attr,
> char *buf)
> {
> - struct intel_vgpu_type *type;
> - unsigned int num = 0;
> - struct intel_gvt *gvt =
> kdev_to_i915(mtype_get_parent_dev(mtype))->gvt;
> + struct intel_vgpu_type *type =
> + container_of(mtype, struct intel_vgpu_type, type);
>
> - type = &gvt->types[mtype_get_type_group_id(mtype)];
> - if (!type)
> - num = 0;
> - else
> - num = type->avail_instance;
> -
> - return sprintf(buf, "%u\n", num);
> + return sprintf(buf, "%u\n", type->avail_instance);
> }
>
> static ssize_t device_api_show(struct mdev_type *mtype,
> @@ -139,12 +132,8 @@ static ssize_t device_api_show(struct mdev_type
> *mtype,
> static ssize_t description_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr,
> char *buf)
> {
> - struct intel_vgpu_type *type;
> - struct intel_gvt *gvt =
> kdev_to_i915(mtype_get_parent_dev(mtype))->gvt;
> -
> - type = &gvt->types[mtype_get_type_group_id(mtype)];
> - if (!type)
> - return 0;
> + struct intel_vgpu_type *type =
> + container_of(mtype, struct intel_vgpu_type, type);
>
> return sprintf(buf, "low_gm_size: %dMB\nhigh_gm_size: %dMB\n"
> "fence: %d\nresolution: %s\n"
> @@ -158,14 +147,7 @@ static ssize_t description_show(struct mdev_type
> *mtype,
> static ssize_t name_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr, char *buf)
> {
> - struct intel_vgpu_type *type;
> - struct intel_gvt *gvt =
> kdev_to_i915(mtype_get_parent_dev(mtype))->gvt;
> -
> - type = &gvt->types[mtype_get_type_group_id(mtype)];
> - if (!type)
> - return 0;
> -
> - return sprintf(buf, "%s\n", type->name);
> + return sprintf(buf, "%s\n", mtype->sysfs_name);
> }
>
> static MDEV_TYPE_ATTR_RO(available_instances);
> @@ -173,7 +155,7 @@ static MDEV_TYPE_ATTR_RO(device_api);
> static MDEV_TYPE_ATTR_RO(description);
> static MDEV_TYPE_ATTR_RO(name);
>
> -static struct attribute *gvt_type_attrs[] = {
> +static const struct attribute *gvt_type_attrs[] = {
> &mdev_type_attr_available_instances.attr,
> &mdev_type_attr_device_api.attr,
> &mdev_type_attr_description.attr,
> @@ -181,51 +163,6 @@ static struct attribute *gvt_type_attrs[] = {
> NULL,
> };
>
> -static struct attribute_group *gvt_vgpu_type_groups[] = {
> - [0 ... NR_MAX_INTEL_VGPU_TYPES - 1] = NULL,
> -};
> -
> -static int intel_gvt_init_vgpu_type_groups(struct intel_gvt *gvt)
> -{
> - int i, j;
> - struct intel_vgpu_type *type;
> - struct attribute_group *group;
> -
> - for (i = 0; i < gvt->num_types; i++) {
> - type = &gvt->types[i];
> -
> - group = kzalloc(sizeof(struct attribute_group),
> GFP_KERNEL);
> - if (!group)
> - goto unwind;
> -
> - group->name = type->name;
> - group->attrs = gvt_type_attrs;
> - gvt_vgpu_type_groups[i] = group;
> - }
> -
> - return 0;
> -
> -unwind:
> - for (j = 0; j < i; j++) {
> - group = gvt_vgpu_type_groups[j];
> - kfree(group);
> - }
> -
> - return -ENOMEM;
> -}
> -
> -static void intel_gvt_cleanup_vgpu_type_groups(struct intel_gvt
> *gvt)
> -{
> - int i;
> - struct attribute_group *group;
> -
> - for (i = 0; i < gvt->num_types; i++) {
> - group = gvt_vgpu_type_groups[i];
> - gvt_vgpu_type_groups[i] = NULL;
> - kfree(group);
> - }
> -}
> -
> static void gvt_unpin_guest_page(struct intel_vgpu *vgpu, unsigned
> long gfn,
> unsigned long size)
> {
> @@ -1547,16 +1484,11 @@ static const struct attribute_group
> *intel_vgpu_groups[] = {
> static int intel_vgpu_init_dev(struct vfio_device *vfio_dev)
> {
> struct mdev_device *mdev = to_mdev_device(vfio_dev->dev);
> - struct device *pdev = mdev_parent_dev(mdev);
> - struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
> - struct intel_vgpu_type *type;
> struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
> + struct intel_vgpu_type *type =
> + container_of(mdev->type, struct intel_vgpu_type,
> type);
>
> - type = &gvt->types[mdev_get_type_group_id(mdev)];
> - if (!type)
> - return -EINVAL;
> -
> - vgpu->gvt = gvt;
> + vgpu->gvt = kdev_to_i915(mdev_parent_dev(mdev))->gvt;
> return intel_gvt_create_vgpu(vgpu, type->conf);
> }
>
> @@ -1624,7 +1556,7 @@ static struct mdev_driver
> intel_vgpu_mdev_driver = {
> },
> .probe = intel_vgpu_probe,
> .remove = intel_vgpu_remove,
> - .supported_type_groups = gvt_vgpu_type_groups,
> + .types_attrs = gvt_type_attrs,
> };
>
> int intel_gvt_page_track_add(struct intel_vgpu *info, u64 gfn)
> @@ -1923,7 +1855,6 @@ static void intel_gvt_clean_device(struct
> drm_i915_private *i915)
> return;
>
> mdev_unregister_parent(&gvt->parent);
> - intel_gvt_cleanup_vgpu_type_groups(gvt);
> intel_gvt_destroy_idle_vgpu(gvt->idle_vgpu);
> intel_gvt_clean_vgpu_types(gvt);
>
> @@ -2023,20 +1954,15 @@ static int intel_gvt_init_device(struct
> drm_i915_private *i915)
>
> intel_gvt_debugfs_init(gvt);
>
> - ret = intel_gvt_init_vgpu_type_groups(gvt);
> - if (ret)
> - goto out_destroy_idle_vgpu;
> -
> ret = mdev_register_parent(&gvt->parent, i915->drm.dev,
> - &intel_vgpu_mdev_driver);
> + &intel_vgpu_mdev_driver,
> + gvt->mdev_types, gvt->num_types);
> if (ret)
> - goto out_cleanup_vgpu_type_groups;
> + goto out_destroy_idle_vgpu;
>
> gvt_dbg_core("gvt device initialization is done\n");
> return 0;
>
> -out_cleanup_vgpu_type_groups:
> - intel_gvt_cleanup_vgpu_type_groups(gvt);
> out_destroy_idle_vgpu:
> intel_gvt_destroy_idle_vgpu(gvt->idle_vgpu);
> intel_gvt_debugfs_clean(gvt);
> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c
> b/drivers/gpu/drm/i915/gvt/vgpu.c
> index 1b67328c714f1..8fa06d00fd4b9 100644
> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
> @@ -113,13 +113,18 @@ int intel_gvt_init_vgpu_types(struct intel_gvt
> *gvt)
> if (!gvt->types)
> return -ENOMEM;
>
> + gvt->mdev_types = kcalloc(num_types, sizeof(*gvt-
> >mdev_types),
> + GFP_KERNEL);
> + if (!gvt->mdev_types)
> + goto out_free_types;
> +
> for (i = 0; i < num_types; ++i) {
> const struct intel_vgpu_config *conf =
> &intel_vgpu_configs[i];
>
> if (low_avail / conf->low_mm == 0)
> break;
> if (conf->weight < 1 || conf->weight >
> VGPU_MAX_WEIGHT)
> - goto out_free_types;
> + goto out_free_mdev_types;
>
> sprintf(gvt->types[i].name, "GVTg_V%u_%s",
> GRAPHICS_VER(gvt->gt->i915) == 8 ? 4 : 5,
> conf->name);
> @@ -131,11 +136,16 @@ int intel_gvt_init_vgpu_types(struct intel_gvt
> *gvt)
> i, gvt->types[i].name, gvt-
> >types[i].avail_instance,
> conf->low_mm, conf->high_mm, conf-
> >fence,
> conf->weight, vgpu_edid_str(conf-
> >edid));
> +
> + gvt->mdev_types[i] = &gvt->types[i].type;
> + gvt->mdev_types[i]->sysfs_name = gvt->types[i].name;
> }
>
> gvt->num_types = i;
> return 0;
>
> +out_free_mdev_types:
> + kfree(gvt->mdev_types);
> out_free_types:
> kfree(gvt->types);
> return -EINVAL;
> @@ -143,6 +153,7 @@ int intel_gvt_init_vgpu_types(struct intel_gvt
> *gvt)
>
> void intel_gvt_clean_vgpu_types(struct intel_gvt *gvt)
> {
> + kfree(gvt->mdev_types);
> kfree(gvt->types);
> }
>
> diff --git a/drivers/s390/cio/vfio_ccw_drv.c
> b/drivers/s390/cio/vfio_ccw_drv.c
> index 7d105915bd149..25a5de08b3902 100644
> --- a/drivers/s390/cio/vfio_ccw_drv.c
> +++ b/drivers/s390/cio/vfio_ccw_drv.c
> @@ -202,7 +202,6 @@ static void vfio_ccw_free_private(struct
> vfio_ccw_private *private)
> mutex_destroy(&private->io_mutex);
> kfree(private);
> }
> -
> static int vfio_ccw_sch_probe(struct subchannel *sch)
> {
> struct pmcw *pmcw = &sch->schib.pmcw;
> @@ -221,8 +220,11 @@ static int vfio_ccw_sch_probe(struct subchannel
> *sch)
>
> dev_set_drvdata(&sch->dev, private);
>
> + private->mdev_type.sysfs_name = "io";
> + private->mdev_types[0] = &private->mdev_type;
> ret = mdev_register_parent(&private->parent, &sch->dev,
> - &vfio_ccw_mdev_driver);
> + &vfio_ccw_mdev_driver,
> + private->mdev_types, 1);
> if (ret)
> goto out_free;
>
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c
> index 9a0e0c5ffb1a5..c37e712a4b069 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -69,23 +69,13 @@ static ssize_t available_instances_show(struct
> mdev_type *mtype,
> }
> static MDEV_TYPE_ATTR_RO(available_instances);
>
> -static struct attribute *mdev_types_attrs[] = {
> +static const struct attribute *mdev_types_attrs[] = {
> &mdev_type_attr_name.attr,
> &mdev_type_attr_device_api.attr,
> &mdev_type_attr_available_instances.attr,
> NULL,
> };
>
> -static struct attribute_group mdev_type_group = {
> - .name = "io",
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group *mdev_type_groups[] = {
> - &mdev_type_group,
> - NULL,
> -};
> -
> static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
> {
> struct vfio_ccw_private *private =
> @@ -646,5 +636,5 @@ struct mdev_driver vfio_ccw_mdev_driver = {
> },
> .probe = vfio_ccw_mdev_probe,
> .remove = vfio_ccw_mdev_remove,
> - .supported_type_groups = mdev_type_groups,
> + .types_attrs = mdev_types_attrs,
> };
> diff --git a/drivers/s390/cio/vfio_ccw_private.h
> b/drivers/s390/cio/vfio_ccw_private.h
> index 1a4bfb1b5a808..52caa721ec06c 100644
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -120,6 +120,8 @@ struct vfio_ccw_private {
> struct completion release_comp;
>
> struct mdev_parent parent;
> + struct mdev_type mdev_type;
> + struct mdev_type *mdev_types[1];
> } __aligned(8);
>
> int vfio_ccw_sch_quiesce(struct subchannel *sch);
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index 724d09a74a8f1..24d131c502ca3 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -816,23 +816,13 @@ static ssize_t device_api_show(struct mdev_type
> *mtype,
>
> static MDEV_TYPE_ATTR_RO(device_api);
>
> -static struct attribute *vfio_ap_mdev_type_attrs[] = {
> +static const struct attribute *vfio_ap_mdev_type_attrs[] = {
> &mdev_type_attr_name.attr,
> &mdev_type_attr_device_api.attr,
> &mdev_type_attr_available_instances.attr,
> NULL,
> };
>
> -static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
> - .name = VFIO_AP_MDEV_TYPE_HWVIRT,
> - .attrs = vfio_ap_mdev_type_attrs,
> -};
> -
> -static struct attribute_group *vfio_ap_mdev_type_groups[] = {
> - &vfio_ap_mdev_hwvirt_type_group,
> - NULL,
> -};
> -
> #define MDEV_SHARING_ERR "Userspace may not re-assign queue
> %02lx.%04lx " \
> "already assigned to %s"
>
> @@ -1817,7 +1807,7 @@ static struct mdev_driver vfio_ap_matrix_driver
> = {
> },
> .probe = vfio_ap_mdev_probe,
> .remove = vfio_ap_mdev_remove,
> - .supported_type_groups = vfio_ap_mdev_type_groups,
> + .types_attrs = vfio_ap_mdev_type_attrs,
> };
>
> int vfio_ap_mdev_register(void)
> @@ -1830,8 +1820,11 @@ int vfio_ap_mdev_register(void)
> if (ret)
> return ret;
>
> + matrix_dev->mdev_type.sysfs_name = VFIO_AP_MDEV_TYPE_HWVIRT;
> + matrix_dev->mdev_types[0] = &matrix_dev->mdev_type;
> ret = mdev_register_parent(&matrix_dev->parent, &matrix_dev-
> >device,
> - &vfio_ap_matrix_driver);
> + &vfio_ap_matrix_driver,
> + matrix_dev->mdev_types, 1);
> if (ret)
> goto err_driver;
> return 0;
> diff --git a/drivers/s390/crypto/vfio_ap_private.h
> b/drivers/s390/crypto/vfio_ap_private.h
> index 35165730f5174..441dc8dda380b 100644
> --- a/drivers/s390/crypto/vfio_ap_private.h
> +++ b/drivers/s390/crypto/vfio_ap_private.h
> @@ -53,6 +53,8 @@ struct ap_matrix_dev {
> struct ap_driver *vfio_ap_drv;
> struct mutex guests_lock; /* serializes access to each KVM
> guest */
> struct mdev_parent parent;
> + struct mdev_type mdev_type;
> + struct mdev_type *mdev_types[];
> };
>
> extern struct ap_matrix_dev *matrix_dev;
> diff --git a/drivers/vfio/mdev/mdev_core.c
> b/drivers/vfio/mdev/mdev_core.c
> index fa05ac3396950..2d95a497fd3b2 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -29,26 +29,6 @@ struct device *mdev_parent_dev(struct mdev_device
> *mdev)
> }
> EXPORT_SYMBOL(mdev_parent_dev);
>
> -/*
> - * Return the index in supported_type_groups that this mdev_device
> was created
> - * from.
> - */
> -unsigned int mdev_get_type_group_id(struct mdev_device *mdev)
> -{
> - return mdev->type->type_group_id;
> -}
> -EXPORT_SYMBOL(mdev_get_type_group_id);
> -
> -/*
> - * Used in mdev_type_attribute sysfs functions to return the index
> in the
> - * supported_type_groups that the sysfs is called from.
> - */
> -unsigned int mtype_get_type_group_id(struct mdev_type *mtype)
> -{
> - return mtype->type_group_id;
> -}
> -EXPORT_SYMBOL(mtype_get_type_group_id);
> -
> /*
> * Used in mdev_type_attribute sysfs functions to return the parent
> struct
> * device
> @@ -85,6 +65,8 @@ static int mdev_device_remove_cb(struct device
> *dev, void *data)
> * @parent: parent structure registered
> * @dev: device structure representing parent device.
> * @mdev_driver: Device driver to bind to the newly created mdev
> + * @types: Array of supported mdev types
> + * @nr_types: Number of entries in @types
> *
> * Registers the @parent stucture as a parent for mdev types and
> thus mdev
> * devices. The caller needs to hold a reference on @dev that must
> not be
> @@ -93,20 +75,19 @@ static int mdev_device_remove_cb(struct device
> *dev, void *data)
> * Returns a negative value on error, otherwise 0.
> */
> int mdev_register_parent(struct mdev_parent *parent, struct device
> *dev,
> - struct mdev_driver *mdev_driver)
> + struct mdev_driver *mdev_driver, struct mdev_type
> **types,
> + unsigned int nr_types)
> {
> char *env_string = "MDEV_STATE=registered";
> char *envp[] = { env_string, NULL };
> int ret;
>
> - /* check for mandatory ops */
> - if (!mdev_driver->supported_type_groups)
> - return -EINVAL;
> -
> memset(parent, 0, sizeof(*parent));
> init_rwsem(&parent->unreg_sem);
> parent->dev = dev;
> parent->mdev_driver = mdev_driver;
> + parent->types = types;
> + parent->nr_types = nr_types;
>
> if (!mdev_bus_compat_class) {
> mdev_bus_compat_class =
> class_compat_register("mdev_bus");
> diff --git a/drivers/vfio/mdev/mdev_driver.c
> b/drivers/vfio/mdev/mdev_driver.c
> index 7bd4bb9850e81..1da1ecf76a0d5 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -56,10 +56,9 @@ EXPORT_SYMBOL_GPL(mdev_bus_type);
> **/
> int mdev_register_driver(struct mdev_driver *drv)
> {
> - /* initialize common driver fields */
> + if (!drv->types_attrs)
> + return -EINVAL;
> drv->driver.bus = &mdev_bus_type;
> -
> - /* register with core */
> return driver_register(&drv->driver);
> }
> EXPORT_SYMBOL(mdev_register_driver);
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index 297f911fdc890..ba1b2dbddc0bc 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -13,14 +13,6 @@
> int mdev_bus_register(void);
> void mdev_bus_unregister(void);
>
> -struct mdev_type {
> - struct kobject kobj;
> - struct kobject *devices_kobj;
> - struct mdev_parent *parent;
> - struct list_head next;
> - unsigned int type_group_id;
> -};
> -
> extern const struct attribute_group *mdev_device_groups[];
>
> #define to_mdev_type_attr(_attr) \
> diff --git a/drivers/vfio/mdev/mdev_sysfs.c
> b/drivers/vfio/mdev/mdev_sysfs.c
> index b71ffc5594870..38b4c2466ec43 100644
> --- a/drivers/vfio/mdev/mdev_sysfs.c
> +++ b/drivers/vfio/mdev/mdev_sysfs.c
> @@ -82,7 +82,6 @@ static void mdev_type_release(struct kobject *kobj)
> pr_debug("Releasing group %s\n", kobj->name);
> /* Pairs with the get in add_mdev_supported_type() */
> put_device(type->parent->dev);
> - kfree(type);
> }
>
> static struct kobj_type mdev_type_ktype = {
> @@ -90,35 +89,21 @@ static struct kobj_type mdev_type_ktype = {
> .release = mdev_type_release,
> };
>
> -static struct mdev_type *add_mdev_supported_type(struct mdev_parent
> *parent,
> - unsigned int
> type_group_id)
> +static int mdev_type_add(struct mdev_parent *parent, struct
> mdev_type *type)
> {
> - struct mdev_type *type;
> - struct attribute_group *group =
> - parent->mdev_driver-
> >supported_type_groups[type_group_id];
> int ret;
>
> - if (!group->name) {
> - pr_err("%s: Type name empty!\n", __func__);
> - return ERR_PTR(-EINVAL);
> - }
> -
> - type = kzalloc(sizeof(*type), GFP_KERNEL);
> - if (!type)
> - return ERR_PTR(-ENOMEM);
> -
> type->kobj.kset = parent->mdev_types_kset;
> type->parent = parent;
> /* Pairs with the put in mdev_type_release() */
> get_device(parent->dev);
> - type->type_group_id = type_group_id;
>
> ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype,
> NULL,
> "%s-%s", dev_driver_string(parent-
> >dev),
> - group->name);
> + type->sysfs_name);
> if (ret) {
> kobject_put(&type->kobj);
> - return ERR_PTR(ret);
> + return ret;
> }
>
> ret = sysfs_create_file(&type->kobj,
> &mdev_type_attr_create.attr);
> @@ -131,13 +116,10 @@ static struct mdev_type
> *add_mdev_supported_type(struct mdev_parent *parent,
> goto attr_devices_failed;
> }
>
> - ret = sysfs_create_files(&type->kobj,
> - (const struct attribute **)group-
> >attrs);
> - if (ret) {
> - ret = -ENOMEM;
> + ret = sysfs_create_files(&type->kobj, parent->mdev_driver-
> >types_attrs);
> + if (ret)
> goto attrs_failed;
> - }
> - return type;
> + return 0;
>
> attrs_failed:
> kobject_put(type->devices_kobj);
> @@ -146,78 +128,49 @@ static struct mdev_type
> *add_mdev_supported_type(struct mdev_parent *parent,
> attr_create_failed:
> kobject_del(&type->kobj);
> kobject_put(&type->kobj);
> - return ERR_PTR(ret);
> + return ret;
> }
>
> -static void remove_mdev_supported_type(struct mdev_type *type)
> +static void mdev_type_remove(struct mdev_type *type)
> {
> - struct attribute_group *group =
> - type->parent->mdev_driver-
> >supported_type_groups[type->type_group_id];
> + sysfs_remove_files(&type->kobj, type->parent->mdev_driver-
> >types_attrs);
>
> - sysfs_remove_files(&type->kobj,
> - (const struct attribute **)group->attrs);
> kobject_put(type->devices_kobj);
> sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
> kobject_del(&type->kobj);
> kobject_put(&type->kobj);
> }
>
> -static int add_mdev_supported_type_groups(struct mdev_parent
> *parent)
> -{
> - int i;
> -
> - for (i = 0; parent->mdev_driver->supported_type_groups[i];
> i++) {
> - struct mdev_type *type;
> -
> - type = add_mdev_supported_type(parent, i);
> - if (IS_ERR(type)) {
> - struct mdev_type *ltype, *tmp;
> -
> - list_for_each_entry_safe(ltype, tmp, &parent-
> >type_list,
> - next) {
> - list_del(<ype->next);
> - remove_mdev_supported_type(ltype);
> - }
> - return PTR_ERR(type);
> - }
> - list_add(&type->next, &parent->type_list);
> - }
> - return 0;
> -}
> -
> /* mdev sysfs functions */
> void parent_remove_sysfs_files(struct mdev_parent *parent)
> {
> - struct mdev_type *type, *tmp;
> -
> - list_for_each_entry_safe(type, tmp, &parent->type_list, next)
> {
> - list_del(&type->next);
> - remove_mdev_supported_type(type);
> - }
> + int i;
>
> + for (i = 0; i < parent->nr_types; i++)
> + mdev_type_remove(parent->types[i]);
> kset_unregister(parent->mdev_types_kset);
> }
>
> int parent_create_sysfs_files(struct mdev_parent *parent)
> {
> - int ret;
> + int ret, i;
>
> parent->mdev_types_kset =
> kset_create_and_add("mdev_supported_types",
> NULL, &parent->dev-
> >kobj);
> -
> if (!parent->mdev_types_kset)
> return -ENOMEM;
>
> - INIT_LIST_HEAD(&parent->type_list);
> -
> - ret = add_mdev_supported_type_groups(parent);
> - if (ret)
> - goto create_err;
> + for (i = 0; i < parent->nr_types; i++) {
> + ret = mdev_type_add(parent, parent->types[i]);
> + if (ret)
> + goto out_err;
> + }
> return 0;
>
> -create_err:
> - kset_unregister(parent->mdev_types_kset);
> - return ret;
> +out_err:
> + while (--i >= 0)
> + mdev_type_remove(parent->types[i]);
> + return 0;
> }
>
> static ssize_t remove_store(struct device *dev, struct
> device_attribute *attr,
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 262512c2a8ffc..19bc93c10e8c7 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -23,14 +23,27 @@ struct mdev_device {
> bool active;
> };
>
> +struct mdev_type {
> + /* set by the driver before calling mdev_register parent: */
> + const char *sysfs_name;
> +
> + /* set by the core, can be used drivers */
> + struct mdev_parent *parent;
> +
> + /* internal only */
> + struct kobject kobj;
> + struct kobject *devices_kobj;
> +};
> +
> /* embedded into the struct device that the mdev devices hang off */
> struct mdev_parent {
> struct device *dev;
> struct mdev_driver *mdev_driver;
> struct kset *mdev_types_kset;
> - struct list_head type_list;
> /* Synchronize device creation/removal with parent
> unregistration */
> struct rw_semaphore unreg_sem;
> + struct mdev_type **types;
> + unsigned int nr_types;
> };
>
> static inline struct mdev_device *to_mdev_device(struct device *dev)
> @@ -38,8 +51,6 @@ static inline struct mdev_device
> *to_mdev_device(struct device *dev)
> return container_of(dev, struct mdev_device, dev);
> }
>
> -unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
> -unsigned int mtype_get_type_group_id(struct mdev_type *mtype);
> struct device *mtype_get_parent_dev(struct mdev_type *mtype);
>
> /* interface for exporting mdev supported type attributes */
> @@ -66,22 +77,21 @@ struct mdev_type_attribute mdev_type_attr_##_name
> = \
> * struct mdev_driver - Mediated device driver
> * @probe: called when new device created
> * @remove: called when device removed
> - * @supported_type_groups: Attributes to define supported types. It
> is mandatory
> - * to provide supported types.
> + * @types_attrs: attributes to the type kobjects.
> * @driver: device driver structure
> - *
> **/
> struct mdev_driver {
> int (*probe)(struct mdev_device *dev);
> void (*remove)(struct mdev_device *dev);
> - struct attribute_group **supported_type_groups;
> + const struct attribute * const *types_attrs;
> struct device_driver driver;
> };
>
> extern struct bus_type mdev_bus_type;
>
> int mdev_register_parent(struct mdev_parent *parent, struct device
> *dev,
> - struct mdev_driver *mdev_driver);
> + struct mdev_driver *mdev_driver, struct mdev_type
> **types,
> + unsigned int nr_types);
> void mdev_unregister_parent(struct mdev_parent *parent);
>
> int mdev_register_driver(struct mdev_driver *drv);
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index 2c4791abbc3d3..4d0839cb51943 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -99,23 +99,27 @@ MODULE_PARM_DESC(mem, "megabytes available to "
> MBOCHS_NAME " devices");
> #define MBOCHS_TYPE_2 "medium"
> #define MBOCHS_TYPE_3 "large"
>
> -static const struct mbochs_type {
> +static struct mbochs_type {
> + struct mdev_type type;
> const char *name;
> u32 mbytes;
> u32 max_x;
> u32 max_y;
> } mbochs_types[] = {
> {
> + .type.sysfs_name = MBOCHS_TYPE_1,
> .name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
> .mbytes = 4,
> .max_x = 800,
> .max_y = 600,
> }, {
> + .type.sysfs_name = MBOCHS_TYPE_2,
> .name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
> .mbytes = 16,
> .max_x = 1920,
> .max_y = 1440,
> }, {
> + .type.sysfs_name = MBOCHS_TYPE_3,
> .name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
> .mbytes = 64,
> .max_x = 0,
> @@ -123,6 +127,11 @@ static const struct mbochs_type {
> },
> };
>
> +static struct mdev_type *mbochs_mdev_types[] = {
> + &mbochs_types[0].type,
> + &mbochs_types[1].type,
> + &mbochs_types[2].type,
> +};
>
> static dev_t mbochs_devt;
> static struct class *mbochs_class;
> @@ -510,8 +519,8 @@ static int mbochs_init_dev(struct vfio_device
> *vdev)
> struct mdev_state *mdev_state =
> container_of(vdev, struct mdev_state, vdev);
> struct mdev_device *mdev = to_mdev_device(vdev->dev);
> - const struct mbochs_type *type =
> - &mbochs_types[mdev_get_type_group_id(mdev)];
> + struct mbochs_type *type =
> + container_of(mdev->type, struct mbochs_type, type);
> int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
> int ret = -ENOMEM;
>
> @@ -1345,8 +1354,8 @@ static const struct attribute_group
> *mdev_dev_groups[] = {
> static ssize_t name_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr, char *buf)
> {
> - const struct mbochs_type *type =
> - &mbochs_types[mtype_get_type_group_id(mtype)];
> + struct mbochs_type *type =
> + container_of(mtype, struct mbochs_type, type);
>
> return sprintf(buf, "%s\n", type->name);
> }
> @@ -1355,8 +1364,8 @@ static MDEV_TYPE_ATTR_RO(name);
> static ssize_t description_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr,
> char *buf)
> {
> - const struct mbochs_type *type =
> - &mbochs_types[mtype_get_type_group_id(mtype)];
> + struct mbochs_type *type =
> + container_of(mtype, struct mbochs_type, type);
>
> return sprintf(buf, "virtual display, %d MB video memory\n",
> type ? type->mbytes : 0);
> @@ -1367,8 +1376,8 @@ static ssize_t available_instances_show(struct
> mdev_type *mtype,
> struct mdev_type_attribute
> *attr,
> char *buf)
> {
> - const struct mbochs_type *type =
> - &mbochs_types[mtype_get_type_group_id(mtype)];
> + struct mbochs_type *type =
> + container_of(mtype, struct mbochs_type, type);
> int count = atomic_read(&mbochs_avail_mbytes) / type->mbytes;
>
> return sprintf(buf, "%d\n", count);
> @@ -1382,7 +1391,7 @@ static ssize_t device_api_show(struct mdev_type
> *mtype,
> }
> static MDEV_TYPE_ATTR_RO(device_api);
>
> -static struct attribute *mdev_types_attrs[] = {
> +static const struct attribute *mdev_types_attrs[] = {
> &mdev_type_attr_name.attr,
> &mdev_type_attr_description.attr,
> &mdev_type_attr_device_api.attr,
> @@ -1390,28 +1399,6 @@ static struct attribute *mdev_types_attrs[] =
> {
> NULL,
> };
>
> -static struct attribute_group mdev_type_group1 = {
> - .name = MBOCHS_TYPE_1,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group mdev_type_group2 = {
> - .name = MBOCHS_TYPE_2,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group mdev_type_group3 = {
> - .name = MBOCHS_TYPE_3,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group *mdev_type_groups[] = {
> - &mdev_type_group1,
> - &mdev_type_group2,
> - &mdev_type_group3,
> - NULL,
> -};
> -
> static const struct vfio_device_ops mbochs_dev_ops = {
> .close_device = mbochs_close_device,
> .init = mbochs_init_dev,
> @@ -1431,7 +1418,7 @@ static struct mdev_driver mbochs_driver = {
> },
> .probe = mbochs_probe,
> .remove = mbochs_remove,
> - .supported_type_groups = mdev_type_groups,
> + .types_attrs = mdev_types_attrs,
> };
>
> static const struct file_operations vd_fops = {
> @@ -1476,7 +1463,9 @@ static int __init mbochs_dev_init(void)
> if (ret)
> goto err_class;
>
> - ret = mdev_register_parent(&mbochs_parent, &mbochs_dev,
> &mbochs_driver);
> + ret = mdev_register_parent(&mbochs_parent, &mbochs_dev,
> &mbochs_driver,
> + mbochs_mdev_types,
> + ARRAY_SIZE(mbochs_mdev_types));
> if (ret)
> goto err_device;
>
> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
> index 01f345430b975..4a341f4849e73 100644
> --- a/samples/vfio-mdev/mdpy.c
> +++ b/samples/vfio-mdev/mdpy.c
> @@ -51,7 +51,8 @@ MODULE_PARM_DESC(count, "number of " MDPY_NAME "
> devices");
> #define MDPY_TYPE_2 "xga"
> #define MDPY_TYPE_3 "hd"
>
> -static const struct mdpy_type {
> +static struct mdpy_type {
> + struct mdev_type type;
> const char *name;
> u32 format;
> u32 bytepp;
> @@ -59,18 +60,21 @@ static const struct mdpy_type {
> u32 height;
> } mdpy_types[] = {
> {
> + .type.sysfs_name = MDPY_TYPE_1,
> .name = MDPY_CLASS_NAME "-" MDPY_TYPE_1,
> .format = DRM_FORMAT_XRGB8888,
> .bytepp = 4,
> .width = 640,
> .height = 480,
> }, {
> + .type.sysfs_name = MDPY_TYPE_2,
> .name = MDPY_CLASS_NAME "-" MDPY_TYPE_2,
> .format = DRM_FORMAT_XRGB8888,
> .bytepp = 4,
> .width = 1024,
> .height = 768,
> }, {
> + .type.sysfs_name = MDPY_TYPE_3,
> .name = MDPY_CLASS_NAME "-" MDPY_TYPE_3,
> .format = DRM_FORMAT_XRGB8888,
> .bytepp = 4,
> @@ -79,6 +83,12 @@ static const struct mdpy_type {
> },
> };
>
> +static struct mdev_type *mdpy_mdev_types[] = {
> + &mdpy_types[0].type,
> + &mdpy_types[1].type,
> + &mdpy_types[2].type,
> +};
> +
> static dev_t mdpy_devt;
> static struct class *mdpy_class;
> static struct cdev mdpy_cdev;
> @@ -222,7 +232,7 @@ static int mdpy_init_dev(struct vfio_device
> *vdev)
> container_of(vdev, struct mdev_state, vdev);
> struct mdev_device *mdev = to_mdev_device(vdev->dev);
> const struct mdpy_type *type =
> - &mdpy_types[mdev_get_type_group_id(mdev)];
> + container_of(mdev->type, struct mdpy_type, type);
> u32 fbsize;
> int ret = -ENOMEM;
>
> @@ -655,8 +665,7 @@ static const struct attribute_group
> *mdev_dev_groups[] = {
> static ssize_t name_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr, char *buf)
> {
> - const struct mdpy_type *type =
> - &mdpy_types[mtype_get_type_group_id(mtype)];
> + struct mdpy_type *type = container_of(mtype, struct
> mdpy_type, type);
>
> return sprintf(buf, "%s\n", type->name);
> }
> @@ -665,8 +674,7 @@ static MDEV_TYPE_ATTR_RO(name);
> static ssize_t description_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr,
> char *buf)
> {
> - const struct mdpy_type *type =
> - &mdpy_types[mtype_get_type_group_id(mtype)];
> + struct mdpy_type *type = container_of(mtype, struct
> mdpy_type, type);
>
> return sprintf(buf, "virtual display, %dx%d framebuffer\n",
> type->width, type->height);
> @@ -688,7 +696,7 @@ static ssize_t device_api_show(struct mdev_type
> *mtype,
> }
> static MDEV_TYPE_ATTR_RO(device_api);
>
> -static struct attribute *mdev_types_attrs[] = {
> +static const struct attribute *mdev_types_attrs[] = {
> &mdev_type_attr_name.attr,
> &mdev_type_attr_description.attr,
> &mdev_type_attr_device_api.attr,
> @@ -696,28 +704,6 @@ static struct attribute *mdev_types_attrs[] = {
> NULL,
> };
>
> -static struct attribute_group mdev_type_group1 = {
> - .name = MDPY_TYPE_1,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group mdev_type_group2 = {
> - .name = MDPY_TYPE_2,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group mdev_type_group3 = {
> - .name = MDPY_TYPE_3,
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group *mdev_type_groups[] = {
> - &mdev_type_group1,
> - &mdev_type_group2,
> - &mdev_type_group3,
> - NULL,
> -};
> -
> static const struct vfio_device_ops mdpy_dev_ops = {
> .init = mdpy_init_dev,
> .release = mdpy_release_dev,
> @@ -736,7 +722,7 @@ static struct mdev_driver mdpy_driver = {
> },
> .probe = mdpy_probe,
> .remove = mdpy_remove,
> - .supported_type_groups = mdev_type_groups,
> + .types_attrs = mdev_types_attrs,
> };
>
> static const struct file_operations vd_fops = {
> @@ -779,7 +765,9 @@ static int __init mdpy_dev_init(void)
> if (ret)
> goto err_class;
>
> - ret = mdev_register_parent(&mdpy_parent, &mdpy_dev,
> &mdpy_driver);
> + ret = mdev_register_parent(&mdpy_parent, &mdpy_dev,
> &mdpy_driver,
> + mdpy_mdev_types,
> + ARRAY_SIZE(mdpy_mdev_types));
> if (ret)
> goto err_device;
>
> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
> index e80baac513811..814a7f98738a2 100644
> --- a/samples/vfio-mdev/mtty.c
> +++ b/samples/vfio-mdev/mtty.c
> @@ -143,6 +143,20 @@ struct mdev_state {
> int nr_ports;
> };
>
> +static struct mtty_type {
> + struct mdev_type type;
> + int nr_ports;
> + const char *name;
> +} mtty_types[2] = {
> + { .nr_ports = 1, .type.sysfs_name = "1", .name = "Single port
> serial" },
> + { .nr_ports = 2, .type.sysfs_name = "2", .name = "Dual port
> serial" },
> +};
> +
> +static struct mdev_type *mtty_mdev_types[] = {
> + &mtty_types[0].type,
> + &mtty_types[1].type,
> +};
> +
> static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS);
>
> static const struct file_operations vd_fops = {
> @@ -707,17 +721,19 @@ static int mtty_init_dev(struct vfio_device
> *vdev)
> struct mdev_state *mdev_state =
> container_of(vdev, struct mdev_state, vdev);
> struct mdev_device *mdev = to_mdev_device(vdev->dev);
> - int nr_ports = mdev_get_type_group_id(mdev) + 1;
> + struct mtty_type *type =
> + container_of(mdev->type, struct mtty_type, type);
> int avail_ports = atomic_read(&mdev_avail_ports);
> int ret;
>
> do {
> - if (avail_ports < nr_ports)
> + if (avail_ports < type->nr_ports)
> return -ENOSPC;
> } while (!atomic_try_cmpxchg(&mdev_avail_ports,
> - &avail_ports, avail_ports -
> nr_ports));
> + &avail_ports,
> + avail_ports - type->nr_ports));
>
> - mdev_state->nr_ports = nr_ports;
> + mdev_state->nr_ports = type->nr_ports;
> mdev_state->irq_index = -1;
> mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
> mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
> @@ -735,7 +751,7 @@ static int mtty_init_dev(struct vfio_device
> *vdev)
> return 0;
>
> err_nr_ports:
> - atomic_add(nr_ports, &mdev_avail_ports);
> + atomic_add(type->nr_ports, &mdev_avail_ports);
> return ret;
> }
>
> @@ -1242,11 +1258,9 @@ static const struct attribute_group
> *mdev_dev_groups[] = {
> static ssize_t name_show(struct mdev_type *mtype,
> struct mdev_type_attribute *attr, char *buf)
> {
> - static const char *name_str[2] = { "Single port serial",
> - "Dual port serial" };
> + struct mtty_type *type = container_of(mtype, struct
> mtty_type, type);
>
> - return sysfs_emit(buf, "%s\n",
> - name_str[mtype_get_type_group_id(mtype)]);
> + return sysfs_emit(buf, "%s\n", type->name);
> }
>
> static MDEV_TYPE_ATTR_RO(name);
> @@ -1255,9 +1269,10 @@ static ssize_t available_instances_show(struct
> mdev_type *mtype,
> struct mdev_type_attribute
> *attr,
> char *buf)
> {
> - unsigned int ports = mtype_get_type_group_id(mtype) + 1;
> + struct mtty_type *type = container_of(mtype, struct
> mtty_type, type);
>
> - return sprintf(buf, "%d\n", atomic_read(&mdev_avail_ports) /
> ports);
> + return sprintf(buf, "%d\n", atomic_read(&mdev_avail_ports) /
> + type->nr_ports);
> }
>
> static MDEV_TYPE_ATTR_RO(available_instances);
> @@ -1270,29 +1285,13 @@ static ssize_t device_api_show(struct
> mdev_type *mtype,
>
> static MDEV_TYPE_ATTR_RO(device_api);
>
> -static struct attribute *mdev_types_attrs[] = {
> +static const struct attribute *mdev_types_attrs[] = {
> &mdev_type_attr_name.attr,
> &mdev_type_attr_device_api.attr,
> &mdev_type_attr_available_instances.attr,
> NULL,
> };
>
> -static struct attribute_group mdev_type_group1 = {
> - .name = "1",
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group mdev_type_group2 = {
> - .name = "2",
> - .attrs = mdev_types_attrs,
> -};
> -
> -static struct attribute_group *mdev_type_groups[] = {
> - &mdev_type_group1,
> - &mdev_type_group2,
> - NULL,
> -};
> -
> static const struct vfio_device_ops mtty_dev_ops = {
> .name = "vfio-mtty",
> .init = mtty_init_dev,
> @@ -1311,7 +1310,7 @@ static struct mdev_driver mtty_driver = {
> },
> .probe = mtty_probe,
> .remove = mtty_remove,
> - .supported_type_groups = mdev_type_groups,
> + .types_attrs = mdev_types_attrs,
> };
>
> static void mtty_device_release(struct device *dev)
> @@ -1363,7 +1362,8 @@ static int __init mtty_dev_init(void)
> goto err_class;
>
> ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev,
> - &mtty_driver);
> + &mtty_driver, mtty_mdev_types,
> + ARRAY_SIZE(mtty_mdev_types));
> if (ret)
> goto err_device;
> return 0;
