vfio-mdev: Make mdev_device private and abstract interfaces

Abstract access to mdev_device so that we can define which interfaces
are public rather than relying on comments in the structure.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

5 files changed, 71 insertions, 45 deletions

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 38500329aa92..f8021a01df63 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -166,7 +166,7 @@ static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
 
 static void gvt_cache_remove(struct intel_vgpu *vgpu, gfn_t gfn)
 {
-        struct device *dev = &vgpu->vdev.mdev->dev;
+        struct device *dev = mdev_dev(vgpu->vdev.mdev);
         struct gvt_dma *this;
         unsigned long g1;
         int rc;
@@ -195,7 +195,7 @@ static void gvt_cache_destroy(struct intel_vgpu *vgpu)
 {
         struct gvt_dma *dma;
         struct rb_node *node = NULL;
-        struct device *dev = &vgpu->vdev.mdev->dev;
+        struct device *dev = mdev_dev(vgpu->vdev.mdev);
         unsigned long gfn;
 
         mutex_lock(&vgpu->vdev.cache_lock);
@@ -418,7 +418,7 @@ static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
         mdev_set_drvdata(mdev, vgpu);
 
         gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
-                     dev_name(&mdev->dev));
+                     dev_name(mdev_dev(mdev)));
         return 0;
 }
 
@@ -482,7 +482,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
         vgpu->vdev.group_notifier.notifier_call = intel_vgpu_group_notifier;
 
         events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
-        ret = vfio_register_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, &events,
+        ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &events,
                                 &vgpu->vdev.iommu_notifier);
         if (ret != 0) {
                 gvt_err("vfio_register_notifier for iommu failed: %d\n", ret);
@@ -490,7 +490,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
         }
 
         events = VFIO_GROUP_NOTIFY_SET_KVM;
-        ret = vfio_register_notifier(&mdev->dev, VFIO_GROUP_NOTIFY, &events,
+        ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, &events,
                                 &vgpu->vdev.group_notifier);
         if (ret != 0) {
                 gvt_err("vfio_register_notifier for group failed: %d\n", ret);
@@ -500,7 +500,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
         return kvmgt_guest_init(mdev);
 
 undo_iommu:
-        vfio_unregister_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY,
+        vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
                                         &vgpu->vdev.iommu_notifier);
 out:
         return ret;
@@ -513,9 +513,9 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
         if (!handle_valid(vgpu->handle))
                 return;
 
-        vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_IOMMU_NOTIFY,
+        vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_IOMMU_NOTIFY,
                                         &vgpu->vdev.iommu_notifier);
-        vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_GROUP_NOTIFY,
+        vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_GROUP_NOTIFY,
                                         &vgpu->vdev.group_notifier);
 
         info = (struct kvmgt_guest_info *)vgpu->handle;
@@ -1372,7 +1372,7 @@ static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
                 return pfn;
 
         pfn = INTEL_GVT_INVALID_ADDR;
-        dev = &info->vgpu->vdev.mdev->dev;
+        dev = mdev_dev(info->vgpu->vdev.mdev);
         rc = vfio_pin_pages(dev, &gfn, 1, IOMMU_READ | IOMMU_WRITE, &pfn);
         if (rc != 1) {
                 gvt_err("vfio_pin_pages failed for gfn 0x%lx: %d\n", gfn, rc);
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 30d05304241e..36d75c367d22 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -36,6 +36,36 @@ 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);
+
+uuid_le mdev_uuid(struct mdev_device *mdev)
+{
+        return mdev->uuid;
+}
+EXPORT_SYMBOL(mdev_uuid);
+
 static int _find_mdev_device(struct device *dev, void *data)
 {
         struct mdev_device *mdev;
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index b05dd22fc9a6..a9cefd70a705 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -26,6 +26,19 @@ struct mdev_parent {
         struct list_head type_list;
 };
 
+struct mdev_device {
+        struct device dev;
+        struct mdev_parent *parent;
+        uuid_le uuid;
+        void *driver_data;
+        struct kref ref;
+        struct list_head next;
+        struct kobject *type_kobj;
+};
+
+#define to_mdev_device(dev)     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;
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index f586222b6c25..3ee44b8d2bb3 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -13,18 +13,7 @@
 #ifndef MDEV_H
 #define MDEV_H
 
-/* Mediated device */
-struct mdev_device {
-        struct device           dev;
-        struct mdev_parent      *parent;
-        uuid_le                 uuid;
-        void                    *driver_data;
-
-        /* internal */
-        struct kref             ref;
-        struct list_head        next;
-        struct kobject          *type_kobj;
-};
+struct mdev_device;
 
 /**
  * struct mdev_parent_ops - Structure to be registered for each parent device to
@@ -75,7 +64,6 @@ struct mdev_device {
  * Parent device that support mediated device should be registered with mdev
  * module with mdev_parent_ops structure.
  **/
-
 struct mdev_parent_ops {
         struct module   *owner;
         const struct attribute_group **dev_attr_groups;
@@ -129,22 +117,13 @@ struct mdev_driver {
 };
 
 #define to_mdev_driver(drv)     container_of(drv, struct mdev_driver, driver)
-#define to_mdev_device(dev)     container_of(dev, struct mdev_device, dev)
 
-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;
-}
+extern void *mdev_get_drvdata(struct mdev_device *mdev);
+extern void mdev_set_drvdata(struct mdev_device *mdev, void *data);
+extern uuid_le mdev_uuid(struct mdev_device *mdev);
 
 extern struct bus_type mdev_bus_type;
 
-#define dev_is_mdev(d) ((d)->bus == &mdev_bus_type)
-
 extern int  mdev_register_device(struct device *dev,
                                  const struct mdev_parent_ops *ops);
 extern void mdev_unregister_device(struct device *dev);
@@ -153,5 +132,7 @@ extern int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
 extern void mdev_unregister_driver(struct mdev_driver *drv);
 
 extern struct device *mdev_parent_dev(struct mdev_device *mdev);
+extern struct device *mdev_dev(struct mdev_device *mdev);
+extern struct mdev_device *mdev_from_dev(struct device *dev);
 
 #endif /* MDEV_H */
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 5e13efc62bad..919c10d5b12e 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -164,7 +164,7 @@ static struct mdev_state *find_mdev_state_by_uuid(uuid_le uuid)
         struct mdev_state *mds;
 
         list_for_each_entry(mds, &mdev_devices_list, next) {
-                if (uuid_le_cmp(mds->mdev->uuid, uuid) == 0)
+                if (uuid_le_cmp(mdev_uuid(mds->mdev), uuid) == 0)
                         return mds;
         }
 
@@ -341,7 +341,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                                 pr_err("Serial port %d: Fifo level trigger\n",
                                         index);
 #endif
-                                mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                                mtty_trigger_interrupt(
+                                                mdev_uuid(mdev_state->mdev));
                         }
                 } else {
 #if defined(DEBUG_INTR)
@@ -355,7 +356,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                          */
                         if (mdev_state->s[index].uart_reg[UART_IER] &
                                                                 UART_IER_RLSI)
-                                mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                                mtty_trigger_interrupt(
+                                                mdev_uuid(mdev_state->mdev));
                 }
                 mutex_unlock(&mdev_state->rxtx_lock);
                 break;
@@ -374,7 +376,8 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                                 pr_err("Serial port %d: IER_THRI write\n",
                                         index);
 #endif
-                                mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                                mtty_trigger_interrupt(
+                                                mdev_uuid(mdev_state->mdev));
                         }
 
                         mutex_unlock(&mdev_state->rxtx_lock);
@@ -445,7 +448,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
                         pr_err("Serial port %d: MCR_OUT2 write\n", index);
 #endif
-                        mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                        mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
                 }
 
                 if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
@@ -453,7 +456,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
                         pr_err("Serial port %d: MCR RTS/DTR write\n", index);
 #endif
-                        mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                        mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
                 }
                 break;
 
@@ -504,7 +507,8 @@ static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
 #endif
                         if (mdev_state->s[index].uart_reg[UART_IER] &
                                                          UART_IER_THRI)
-                                mtty_trigger_interrupt(mdev_state->mdev->uuid);
+                                mtty_trigger_interrupt(
+                                        mdev_uuid(mdev_state->mdev));
                 }
                 mutex_unlock(&mdev_state->rxtx_lock);
 
@@ -1298,10 +1302,8 @@ static ssize_t
 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
                      char *buf)
 {
-        struct mdev_device *mdev = to_mdev_device(dev);
-
-        if (mdev)
-                return sprintf(buf, "This is MDEV %s\n", dev_name(&mdev->dev));
+        if (mdev_from_dev(dev))
+                return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
 
         return sprintf(buf, "\n");
 }