Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / drivers / vfio / vfio.c

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 1eab4ace06718ac38574414d11de280755de6334..21271d8df02374aaae378c552ff7ad10b89e6e84 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -22,6 +22,7 @@
 #include <linux/idr.h>
 #include <linux/iommu.h>
 #include <linux/list.h>
+#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
@@ -45,9 +46,7 @@ static struct vfio {
        struct idr                      group_idr;
        struct mutex                    group_lock;
        struct cdev                     group_cdev;
-       struct device                   *dev;
-       dev_t                           devt;
-       struct cdev                     cdev;
+       dev_t                           group_devt;
        wait_queue_head_t               release_q;
 } vfio;
 
@@ -142,8 +141,7 @@ EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
  */
 static int vfio_alloc_group_minor(struct vfio_group *group)
 {
-       /* index 0 is used by /dev/vfio/vfio */
-       return idr_alloc(&vfio.group_idr, group, 1, MINORMASK + 1, GFP_KERNEL);
+       return idr_alloc(&vfio.group_idr, group, 0, MINORMASK + 1, GFP_KERNEL);
 }
 
 static void vfio_free_group_minor(int minor)
@@ -243,7 +241,8 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
                }
        }
 
-       dev = device_create(vfio.class, NULL, MKDEV(MAJOR(vfio.devt), minor),
+       dev = device_create(vfio.class, NULL,
+                           MKDEV(MAJOR(vfio.group_devt), minor),
                            group, "%d", iommu_group_id(iommu_group));
        if (IS_ERR(dev)) {
                vfio_free_group_minor(minor);
@@ -268,7 +267,7 @@ static void vfio_group_release(struct kref *kref)
 
        WARN_ON(!list_empty(&group->device_list));
 
-       device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor));
+       device_destroy(vfio.class, MKDEV(MAJOR(vfio.group_devt), group->minor));
        list_del(&group->vfio_next);
        vfio_free_group_minor(group->minor);
        vfio_group_unlock_and_free(group);
@@ -1419,12 +1418,17 @@ EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
  */
 static char *vfio_devnode(struct device *dev, umode_t *mode)
 {
-       if (mode && (MINOR(dev->devt) == 0))
-               *mode = S_IRUGO | S_IWUGO;
-
        return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
 }
 
+static struct miscdevice vfio_dev = {
+       .minor = VFIO_MINOR,
+       .name = "vfio",
+       .fops = &vfio_fops,
+       .nodename = "vfio/vfio",
+       .mode = S_IRUGO | S_IWUGO,
+};
+
 static int __init vfio_init(void)
 {
        int ret;
@@ -1436,6 +1440,13 @@ static int __init vfio_init(void)
        INIT_LIST_HEAD(&vfio.iommu_drivers_list);
        init_waitqueue_head(&vfio.release_q);
 
+       ret = misc_register(&vfio_dev);
+       if (ret) {
+               pr_err("vfio: misc device register failed\n");
+               return ret;
+       }
+
+       /* /dev/vfio/$GROUP */
        vfio.class = class_create(THIS_MODULE, "vfio");
        if (IS_ERR(vfio.class)) {
                ret = PTR_ERR(vfio.class);
@@ -1444,27 +1455,14 @@ static int __init vfio_init(void)
 
        vfio.class->devnode = vfio_devnode;
 
-       ret = alloc_chrdev_region(&vfio.devt, 0, MINORMASK, "vfio");
-       if (ret)
-               goto err_base_chrdev;
-
-       cdev_init(&vfio.cdev, &vfio_fops);
-       ret = cdev_add(&vfio.cdev, vfio.devt, 1);
+       ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK, "vfio");
        if (ret)
-               goto err_base_cdev;
+               goto err_alloc_chrdev;
 
-       vfio.dev = device_create(vfio.class, NULL, vfio.devt, NULL, "vfio");
-       if (IS_ERR(vfio.dev)) {
-               ret = PTR_ERR(vfio.dev);
-               goto err_base_dev;
-       }
-
-       /* /dev/vfio/$GROUP */
        cdev_init(&vfio.group_cdev, &vfio_group_fops);
-       ret = cdev_add(&vfio.group_cdev,
-                      MKDEV(MAJOR(vfio.devt), 1), MINORMASK - 1);
+       ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK);
        if (ret)
-               goto err_groups_cdev;
+               goto err_cdev_add;
 
        pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 
@@ -1478,16 +1476,13 @@ static int __init vfio_init(void)
 
        return 0;
 
-err_groups_cdev:
-       device_destroy(vfio.class, vfio.devt);
-err_base_dev:
-       cdev_del(&vfio.cdev);
-err_base_cdev:
-       unregister_chrdev_region(vfio.devt, MINORMASK);
-err_base_chrdev:
+err_cdev_add:
+       unregister_chrdev_region(vfio.group_devt, MINORMASK);
+err_alloc_chrdev:
        class_destroy(vfio.class);
        vfio.class = NULL;
 err_class:
+       misc_deregister(&vfio_dev);
        return ret;
 }
 
@@ -1497,11 +1492,10 @@ static void __exit vfio_cleanup(void)
 
        idr_destroy(&vfio.group_idr);
        cdev_del(&vfio.group_cdev);
-       device_destroy(vfio.class, vfio.devt);
-       cdev_del(&vfio.cdev);
-       unregister_chrdev_region(vfio.devt, MINORMASK);
+       unregister_chrdev_region(vfio.group_devt, MINORMASK);
        class_destroy(vfio.class);
        vfio.class = NULL;
+       misc_deregister(&vfio_dev);
 }
 
 module_init(vfio_init);
@@ -1511,3 +1505,5 @@ MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_ALIAS_MISCDEV(VFIO_MINOR);
+MODULE_ALIAS("devname:vfio/vfio");