vfio/mdev: Add missing typesafety around mdev_device

The mdev API should accept and pass a 'struct mdev_device *' in all
places, not pass a 'struct device *' and cast it internally with
to_mdev_device(). Particularly in its struct mdev_driver functions, the
whole point of a bus's struct device_driver wrapper is to provide type
safety compared to the default struct device_driver.

Further, the driver core standard is for bus drivers to expose their
device structure in their public headers that can be used with
container_of() inlines and '&foo->dev' to go between the class levels, and
'&foo->dev' to be used with dev_err/etc driver core helper functions. Move
'struct mdev_device' to mdev.h

Once done this allows moving some one instruction exported functions to
static inlines, which in turns allows removing one of the two grotesque
symbol_get()'s related to mdev in the core code.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <3-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 25eb7d5..c43c1dc 100644 (file)
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -105,8 +105,8 @@ structure to represent a mediated device's driver::
       */
      struct mdev_driver {
             const char *name;
-            int  (*probe)  (struct device *dev);
-            void (*remove) (struct device *dev);
+            int  (*probe)  (struct mdev_device *dev);
+            void (*remove) (struct mdev_device *dev);
             struct device_driver    driver;
      };
 

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 6de97d2..057922a 100644 (file)
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -33,36 +33,6 @@ struct device *mdev_parent_dev(struct mdev_device *mdev)
 }
 EXPORT_SYMBOL(mdev_parent_dev);
 
-void *mdev_get_drvdata(struct mdev_device *mdev)
-{
-       return mdev->driver_data;
-}
-EXPORT_SYMBOL(mdev_get_drvdata);
-
-void mdev_set_drvdata(struct mdev_device *mdev, void *data)
-{
-       mdev->driver_data = data;
-}
-EXPORT_SYMBOL(mdev_set_drvdata);
-
-struct device *mdev_dev(struct mdev_device *mdev)
-{
-       return &mdev->dev;
-}
-EXPORT_SYMBOL(mdev_dev);
-
-struct mdev_device *mdev_from_dev(struct device *dev)
-{
-       return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
-}
-EXPORT_SYMBOL(mdev_from_dev);
-
-const guid_t *mdev_uuid(struct mdev_device *mdev)
-{
-       return &mdev->uuid;
-}
-EXPORT_SYMBOL(mdev_uuid);
-
 /* Should be called holding parent_list_lock */
 static struct mdev_parent *__find_parent_device(struct device *dev)
 {
@@ -107,7 +77,7 @@ static void mdev_device_remove_common(struct mdev_device *mdev)
        int ret;
 
        type = to_mdev_type(mdev->type_kobj);
-       mdev_remove_sysfs_files(&mdev->dev, type);
+       mdev_remove_sysfs_files(mdev, type);
        device_del(&mdev->dev);
        parent = mdev->parent;
        lockdep_assert_held(&parent->unreg_sem);
@@ -122,12 +92,10 @@ static void mdev_device_remove_common(struct mdev_device *mdev)
 
 static int mdev_device_remove_cb(struct device *dev, void *data)
 {
-       if (dev_is_mdev(dev)) {
-               struct mdev_device *mdev;
+       struct mdev_device *mdev = mdev_from_dev(dev);
 
-               mdev = to_mdev_device(dev);
+       if (mdev)
                mdev_device_remove_common(mdev);
-       }
        return 0;
 }
 
@@ -332,7 +300,7 @@ int mdev_device_create(struct kobject *kobj,
        if (ret)
                goto add_fail;
 
-       ret = mdev_create_sysfs_files(&mdev->dev, type);
+       ret = mdev_create_sysfs_files(mdev, type);
        if (ret)
                goto sysfs_fail;
 
@@ -354,13 +322,11 @@ mdev_fail:
        return ret;
 }
 
-int mdev_device_remove(struct device *dev)
+int mdev_device_remove(struct mdev_device *mdev)
 {
-       struct mdev_device *mdev, *tmp;
+       struct mdev_device *tmp;
        struct mdev_parent *parent;
 
-       mdev = to_mdev_device(dev);
-
        mutex_lock(&mdev_list_lock);
        list_for_each_entry(tmp, &mdev_list, next) {
                if (tmp == mdev)
@@ -390,24 +356,6 @@ int mdev_device_remove(struct device *dev)
        return 0;
 }
 
-int mdev_set_iommu_device(struct device *dev, struct device *iommu_device)
-{
-       struct mdev_device *mdev = to_mdev_device(dev);
-
-       mdev->iommu_device = iommu_device;
-
-       return 0;
-}
-EXPORT_SYMBOL(mdev_set_iommu_device);
-
-struct device *mdev_get_iommu_device(struct device *dev)
-{
-       struct mdev_device *mdev = to_mdev_device(dev);
-
-       return mdev->iommu_device;
-}
-EXPORT_SYMBOL(mdev_get_iommu_device);
-
 static int __init mdev_init(void)
 {
        return mdev_bus_register();

diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 0d3223a..44c3ba7 100644 (file)
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -48,7 +48,7 @@ static int mdev_probe(struct device *dev)
                return ret;
 
        if (drv && drv->probe) {
-               ret = drv->probe(dev);
+               ret = drv->probe(mdev);
                if (ret)
                        mdev_detach_iommu(mdev);
        }
@@ -62,7 +62,7 @@ static int mdev_remove(struct device *dev)
        struct mdev_device *mdev = to_mdev_device(dev);
 
        if (drv && drv->remove)
-               drv->remove(dev);
+               drv->remove(mdev);
 
        mdev_detach_iommu(mdev);
 

diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index fdbb3be..97e2225 100644 (file)
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -24,23 +24,6 @@ struct mdev_parent {
        struct rw_semaphore unreg_sem;
 };
 
-struct mdev_device {
-       struct device dev;
-       struct mdev_parent *parent;
-       guid_t uuid;
-       void *driver_data;
-       struct list_head next;
-       struct kobject *type_kobj;
-       struct device *iommu_device;
-       bool active;
-};
-
-static inline struct mdev_device *to_mdev_device(struct device *dev)
-{
-       return container_of(dev, struct mdev_device, dev);
-}
-#define dev_is_mdev(d)         ((d)->bus == &mdev_bus_type)
-
 struct mdev_type {
        struct kobject kobj;
        struct kobject *devices_kobj;
@@ -57,11 +40,11 @@ struct mdev_type {
 int  parent_create_sysfs_files(struct mdev_parent *parent);
 void parent_remove_sysfs_files(struct mdev_parent *parent);
 
-int  mdev_create_sysfs_files(struct device *dev, struct mdev_type *type);
-void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type);
+int  mdev_create_sysfs_files(struct mdev_device *mdev, struct mdev_type *type);
+void mdev_remove_sysfs_files(struct mdev_device *mdev, struct mdev_type *type);
 
 int  mdev_device_create(struct kobject *kobj,
                        struct device *dev, const guid_t *uuid);
-int  mdev_device_remove(struct device *dev);
+int  mdev_device_remove(struct mdev_device *dev);
 
 #endif /* MDEV_PRIVATE_H */

diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 367ff54..18114f3 100644 (file)
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -225,6 +225,7 @@ create_err:
 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
 {
+       struct mdev_device *mdev = to_mdev_device(dev);
        unsigned long val;
 
        if (kstrtoul(buf, 0, &val) < 0)
@@ -233,7 +234,7 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
        if (val && device_remove_file_self(dev, attr)) {
                int ret;
 
-               ret = mdev_device_remove(dev);
+               ret = mdev_device_remove(mdev);
                if (ret)
                        return ret;
        }
@@ -248,34 +249,37 @@ static const struct attribute *mdev_device_attrs[] = {
        NULL,
 };
 
-int  mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
+int mdev_create_sysfs_files(struct mdev_device *mdev, struct mdev_type *type)
 {
+       struct kobject *kobj = &mdev->dev.kobj;
        int ret;
 
-       ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
+       ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev));
        if (ret)
                return ret;
 
-       ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
+       ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");
        if (ret)
                goto type_link_failed;
 
-       ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
+       ret = sysfs_create_files(kobj, mdev_device_attrs);
        if (ret)
                goto create_files_failed;
 
        return ret;
 
 create_files_failed:
-       sysfs_remove_link(&dev->kobj, "mdev_type");
+       sysfs_remove_link(kobj, "mdev_type");
 type_link_failed:
-       sysfs_remove_link(type->devices_kobj, dev_name(dev));
+       sysfs_remove_link(type->devices_kobj, dev_name(&mdev->dev));
        return ret;
 }
 
-void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type)
+void mdev_remove_sysfs_files(struct mdev_device *mdev, struct mdev_type *type)
 {
-       sysfs_remove_files(&dev->kobj, mdev_device_attrs);
-       sysfs_remove_link(&dev->kobj, "mdev_type");
-       sysfs_remove_link(type->devices_kobj, dev_name(dev));
+       struct kobject *kobj = &mdev->dev.kobj;
+
+       sysfs_remove_files(kobj, mdev_device_attrs);
+       sysfs_remove_link(kobj, "mdev_type");
+       sysfs_remove_link(type->devices_kobj, dev_name(&mdev->dev));
 }

diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index ae7e322..91b7b8b 100644 (file)
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -124,9 +124,8 @@ static const struct vfio_device_ops vfio_mdev_dev_ops = {
        .request        = vfio_mdev_request,
 };
 
-static int vfio_mdev_probe(struct device *dev)
+static int vfio_mdev_probe(struct mdev_device *mdev)
 {
-       struct mdev_device *mdev = to_mdev_device(dev);
        struct vfio_device *vdev;
        int ret;
 
@@ -144,9 +143,9 @@ static int vfio_mdev_probe(struct device *dev)
        return 0;
 }
 
-static void vfio_mdev_remove(struct device *dev)
+static void vfio_mdev_remove(struct mdev_device *mdev)
 {
-       struct vfio_device *vdev = dev_get_drvdata(dev);
+       struct vfio_device *vdev = dev_get_drvdata(&mdev->dev);
 
        vfio_unregister_group_dev(vdev);
        kfree(vdev);

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 5fb1bb5..53b4a63 100644 (file)
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1933,28 +1933,13 @@ static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
        return ret;
 }
 
-static struct device *vfio_mdev_get_iommu_device(struct device *dev)
-{
-       struct device *(*fn)(struct device *dev);
-       struct device *iommu_device;
-
-       fn = symbol_get(mdev_get_iommu_device);
-       if (fn) {
-               iommu_device = fn(dev);
-               symbol_put(mdev_get_iommu_device);
-
-               return iommu_device;
-       }
-
-       return NULL;
-}
-
 static int vfio_mdev_attach_domain(struct device *dev, void *data)
 {
+       struct mdev_device *mdev = to_mdev_device(dev);
        struct iommu_domain *domain = data;
        struct device *iommu_device;
 
-       iommu_device = vfio_mdev_get_iommu_device(dev);
+       iommu_device = mdev_get_iommu_device(mdev);
        if (iommu_device) {
                if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
                        return iommu_aux_attach_device(domain, iommu_device);
@@ -1967,10 +1952,11 @@ static int vfio_mdev_attach_domain(struct device *dev, void *data)
 
 static int vfio_mdev_detach_domain(struct device *dev, void *data)
 {
+       struct mdev_device *mdev = to_mdev_device(dev);
        struct iommu_domain *domain = data;
        struct device *iommu_device;
 
-       iommu_device = vfio_mdev_get_iommu_device(dev);
+       iommu_device = mdev_get_iommu_device(mdev);
        if (iommu_device) {
                if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
                        iommu_aux_detach_device(domain, iommu_device);
@@ -2018,9 +2004,10 @@ static bool vfio_bus_is_mdev(struct bus_type *bus)
 
 static int vfio_mdev_iommu_device(struct device *dev, void *data)
 {
+       struct mdev_device *mdev = to_mdev_device(dev);
        struct device **old = data, *new;
 
-       new = vfio_mdev_get_iommu_device(dev);
+       new = mdev_get_iommu_device(mdev);
        if (!new || (*old && *old != new))
                return -EINVAL;
 

diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 27eb383..52f7ea1 100644 (file)
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -10,7 +10,21 @@
 #ifndef MDEV_H
 #define MDEV_H
 
-struct mdev_device;
+struct mdev_device {
+       struct device dev;
+       struct mdev_parent *parent;
+       guid_t uuid;
+       void *driver_data;
+       struct list_head next;
+       struct kobject *type_kobj;
+       struct device *iommu_device;
+       bool active;
+};
+
+static inline struct mdev_device *to_mdev_device(struct device *dev)
+{
+       return container_of(dev, struct mdev_device, dev);
+}
 
 /*
  * Called by the parent device driver to set the device which represents
@@ -19,12 +33,17 @@ struct mdev_device;
  *
  * @dev: the mediated device that iommu will isolate.
  * @iommu_device: a pci device which represents the iommu for @dev.
- *
- * Return 0 for success, otherwise negative error value.
  */
-int mdev_set_iommu_device(struct device *dev, struct device *iommu_device);
+static inline void mdev_set_iommu_device(struct mdev_device *mdev,
+                                        struct device *iommu_device)
+{
+       mdev->iommu_device = iommu_device;
+}
 
-struct device *mdev_get_iommu_device(struct device *dev);
+static inline struct device *mdev_get_iommu_device(struct mdev_device *mdev)
+{
+       return mdev->iommu_device;
+}
 
 /**
  * struct mdev_parent_ops - Structure to be registered for each parent device to
@@ -126,16 +145,25 @@ struct mdev_type_attribute mdev_type_attr_##_name =               \
  **/
 struct mdev_driver {
        const char *name;
-       int  (*probe)(struct device *dev);
-       void (*remove)(struct device *dev);
+       int (*probe)(struct mdev_device *dev);
+       void (*remove)(struct mdev_device *dev);
        struct device_driver driver;
 };
 
 #define to_mdev_driver(drv)    container_of(drv, struct mdev_driver, driver)
 
-void *mdev_get_drvdata(struct mdev_device *mdev);
-void mdev_set_drvdata(struct mdev_device *mdev, void *data);
-const guid_t *mdev_uuid(struct mdev_device *mdev);
+static inline void *mdev_get_drvdata(struct mdev_device *mdev)
+{
+       return mdev->driver_data;
+}
+static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
+{
+       mdev->driver_data = data;
+}
+static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
+{
+       return &mdev->uuid;
+}
 
 extern struct bus_type mdev_bus_type;
 
@@ -146,7 +174,13 @@ int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
 void mdev_unregister_driver(struct mdev_driver *drv);
 
 struct device *mdev_parent_dev(struct mdev_device *mdev);
-struct device *mdev_dev(struct mdev_device *mdev);
-struct mdev_device *mdev_from_dev(struct device *dev);
+static inline struct device *mdev_dev(struct mdev_device *mdev)
+{
+       return &mdev->dev;
+}
+static inline struct mdev_device *mdev_from_dev(struct device *dev)
+{
+       return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
+}
 
 #endif /* MDEV_H */